This is really good - especially for your first attempt at writing angst, you did very well! I think Myrtle was a wonderful choice for that quote - she is a very overlooked character because in the books she just wails a lot and is actually quite comical. But you've given so much depth to her character in the things she wishes she could do. The pain she feels is very tangible (...which is ironic because she's a ghost) and I think you did a great job conveying it.

I think it was really believable too, most of all because of the back story you've given her - how she loved to read, she had a boyfriend, she was happy - and then seeing the future generations of Hogwarts living what she could not (for decades!) it would make anyone bitter. And I really like the way you contrasted her angry feelings with the sunlight streaming through the window, it was really nice.

There are a couple things you could fix if you want - a few small grammar and spelling issues. And also the beginning - I like the idea of starting it off with a bunch of feelings, but some are adjectives and some are nouns, and some are just really similar ("dead" and "death" are both in there), and then it rather abruptly hops to the narration of the story. I think if you changed them all to the same part of speech ie. all adjectives or something, and then added like one sentence at the beginning of the narration to ease in, it would flow a lot better, such as: "I can't shake these feelings as I see the sun streaming through the broken panels of the windows..." etc.

Overall though, this was really well done! You should give yourself a pat on the back for going out of your comfort zone and writing something so good!

I'm happy that my choice of character is appreciated too, because most people really don't like Myrtle. I didn't give her much thought either, till I got this quote. Then I thought that she just seemed to fit the quote, so I went ahead and wrote it.

I'm pleased that you think I did a good job with characterization. And that you liked how I've conveyed her pain. I feel that the back story makes her more relate-able, I'm glad you found that too!

I'm going to give this another read, and I will definitely fix that! :) I didn't realize how odd the assortment of words seem, in a sense. I'll change that fix up the grammar. Hopefully, I'll improve the flow too.